The architectonic moldings are decorative parts used to provide certain volume to the surfaces, granting aesthetic value to walls and other elements in all types of constructions. Although architectonic moldings are used to a great extent for indoor and outdoor constructions, the latter require of deterioration-resistant materials, which are to be exposed to rain, sun and, in general, weathering deterioration. Due to the above, in the construction of this type of outdoor moldings, the use of materials such as cement is common. In contrast, architectonic moldings for interiors allow a greater variety of materials, such as wood, plaster, plastic, among others.
The visible and exposed part of the architectonic molding is usually decorated or finished to give a pleasant aspect, wherein a smooth and uniform surface generally corresponds to the preferred finishing.
However, the traditional methods for the construction of outdoor architectonic moldings include in-site manufacturing in site these items by means of techniques as the use of wood molds into which concrete is casted and the use of a rake that is swept by the cement mixtures and creates the moldings in-site, just where they will remain installed.
Lately, the use of coated expanded polystyrene has replaced these methods, being less time consuming and easier in construction.
Particularly, for polystyrene moldings made in site the typical method consists in attaching section of polystyrene to the outer wall, placing a section of fiberglass mesh, and coating it with some appropriate material. This is done manually with the aid of spatulas or blades. The limitations of this method is that the thickness of the applied coating is usually uneven, with an irregular finishing of texture, in addition, the corners and contours of the molding present a curved finishing in the section where straight contours are desired, as a result of the technique of brush and blade which is usually used. All these causes the molding to lack of adequate general resistance, and therefore fissures and cracking tend to appear, in addition to showing a general low quality appearance.
Additionally, all the methods described for manufacturing outdoor moldings, require an intense and specialized manual dexterity, reason why they are expensive, hardly available, and practically impossible to use by the general public due the requirement of experience and hand labor specialization.
Recently, methods and equipment have appeared tending to automate and to improve the process of coating the polystyrene pieces, such as those used as architectonic moldings. Those described in Canadian Patent No. CA 2.184.205 and U.S. Pat. No. 6,206,965 stand out.
The Canadian patent discloses a method and apparatus to apply a coating to the surface of a piece. In said method, the piece to be coated slides through an open coating chamber, where the material is adhered to the piece by virtue of the characteristics and weight of material itself. The piece is guided and moved on top of a table, by the action of power-driven sideboards, that introduce it into the coating chamber having contoured entrance ports that match the shape of the piece, and an exit port similarly shaped to match the piece shape, but proportionally bigger in such a way that the difference between the dimensions of the piece and the exit port correspond to the thickness of the coating.
U.S. Pat. No. 6,206,965 basically uses the same principle of the coating chamber, but with the difference that this one is closed and the material it is provided by means of controlled pressure conditions; in addition, the piece is moved by the action of a conveying band, located in the horizontal part of the table.
The methods and apparatuses disclosed in Canadian Patent No. CA 2.184.205, and U.S. Pat. No. 6,206,965 work relatively well if the critical aspects of the process are taken care of, namely keeping control of the accuracy of the dimensions between the piece to be coated, the entrance port and the exit port of the chamber; keeping constant the movement of the piece, without vertical nor horizontal variations; and keeping suitable consistency and workability of the coating material. Nevertheless, these apparatuses and methods have some disadvantages, they have a low versatility, because both are unidirectional, and are designed to only provide a single model or shape of the molding per apparatus, and per cycle of operation.
Despite what is previously described in the technical field, there is still a need for a method and apparatus for producing at a commercial scale and low cost architectonic moldings for indoor and outdoor use, that are easy to install by non-skilled persons, versatile, productive, reliable, and simple in its operation.